Speed boat



Aug. 30, 1932. J. PLUM SPEED BOAT Filed Jan. 28, 1951 2 Sheets-Sheet l RFS/6 74A/CE mventox:y

o u. e n r. o nu a Patented Aug. 30, 1932 UNITED STATES NIMES PATENT OFFICE JOHANNESv PLUM, OF WASHINGTON, DISTRICT OF COLUMBIA, ASSIGNOR TO FANTAIL BOAT CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK SPEED BOAT Application filed January 28,' 1931.

This invention relates to new and useful improvements in speed boats of the hydroplane type.

The main object is to provide a boat of the planing type with means of sucha nature as will permit the boat, together with a heavy load carried thereby, to be raised to the water surface for the planing condition.

With these and other objects in view which will more fully appear, the nature of the nvention will be. more 'clearly understood by following the description, the appended claims, andthe several views illustrated 1n thev accompanying drawings.

In the accompanying drawings Figure l is a top plan view of a speed boat embodying invention,

Figure 2 shows the position of the sternplane when the boat has been adjustedto the optimal planing-angle` and is skimming vover the surface,

Figure 3 is a top plan view thereof,

Figure 4 is a cross sectional view taken on the line l-t of Figure 3,

Figure 5 is a diagrammatic view showing the fluid pressure circuits for controlling the sternplane,

Figure 6 is an enlarged sectional view of the valve for adjusting the boat to the optimal trim-angle,

Figure 7 is an enlarged sectional View of the valve for controlling the planing angle of the boat, and Y Figure 8 is, a view of a chart showing certain curves and the component thereof.

When the functions of a hydroplane speed boat are considered, the differences between two important conditions must be clearly understood. Y

The first condition exists during the period the boat is endeavoring to gain sufficient speed to give its bottom portion so much dynamic lift that it will rise to the surface for planing action. l

The second condition comes into effect when and after the boat has obtained planing action.

During the first condition the boat functions mostly as a displacement boat carried by the water it displaces, and the object Serial No. 511,853.

should be to give the boat the best angle of i trim relative to the horizontal which from the very start will produce the greatest lift with the smallest resistance. I have called this angle of trim the optimal trim-angle because it is the trim which gives the maximum ratio of lift to drag. I have found that the optimal trim-angle is a function of the ratio ofthe beam to the length of the bottom portion receiving dynamic lift when the boat is moving forwardly, so that the smaller the ratio the greater will be the optimal trimangle. During the first period of the boats run, its whole bottom portion from the step to the bow receives dynamic lift and consequently the ratio of beam to length is small and the optimal trim-angle is large. However, as the speed is accelerated and the boat lifted to some extent the length of the bottom portion which receives dynamic lift is decreased, while the beam remains constant, and consequently the ratio of beam to length increases and the optimal trim-angle decreases. In other words, I have found that the optimal trim-angle of a hydroplane speed boat varies with speed being greatest at low speeds. I have furthermore found that if the optimal trim-angle can be attained during the period of the first condition when the boat endeavors to rise to the water surface, much greater loads can be successfully lifted to the surface for the planing condition than otherwise would be. The structure disclosed in the accompanying drawings shows means for varying the trim angle of the boat. It is quite clear that by changing the inclination of the axis on which the plane swings, will change the pitch of the plane, i. e.l` its angle relative to the water line, and that the changing of this angle will necessarily change the angle of trim of the whole boat. During the first period of the first condition when the object is to produce the greatest ratio of lift to drag, the plane functions in the same manner as the horizontal rudder of a submarine, which also controls the angle of trim of the craft when it moves forward through the water.

During the second condition, when the boatfhas obtained planing action, it is mostly carried by the dynamic lift of the water. have rfound that the most eiiicient planing action of a hydroplane boatinvolves a delicate balance between the planingv area, the plan-k ing angle and the speed. At each speed for y i any given hull lines there is an angleffor which the total resistance -is 'definitely 1.a l minimum. I have called this angle the optimalplaning-angle? because it isthe angle givingfthe best speedwitha given power or, in other words, it is the-angle requiring Y the least power fora given speed. The great importance and the critical nature of the opl timal planing angle are clearly yshownjloyy means of the kdiagram shown in Figure 8. In this figure there are three curves respective-ly representing the total resistanceand its two components as a function of the angle of trim".` The curve -marlredw indicates 'the wave-making or turbulence resistance which has aminimumvalue' at zero degrees and increasesv as thel angle of trim is increased. The curve marked yvindicates the resistance due tothe viscosity of the water which is usually called skinfriction. vlt is greatest at zero degrees where lthe wetted surface of the planing areaof the boat is greatest and' it decreases as the angle of trim isincreased. The curve marked y@indicates the total re# sistance or the sum of the wave-making and ythe viscuous resistances. i The total resistance iscolnparatively large at Zero degrees,and as .the-angle of trim is increased', it first `decreasesto minimum'value at the optimal planing-angle and then "increases again. These curves are schematic only and are intended to illustrate the relation existing/at some given speed." Similar curves exist for each speed with a given set of hull lines. My tests'have shown that the optimal angle (alpha) is almost entirely a function of the linesl of the planing surface and the speed, and ,that it is apparently not affected by the load carried. vI have found that the optimal planing-angle varies; inversely with planing speed in accordancewith an empirical equation of the form e a". V+K2 whereV is the speed in miles per hour and Kg and K2 are constants for any given .setof lines. The average value of K1 and K2 appears to be 'lOOand 10 respectively 'so that f 'g v100 i and the average variation' ofthe optimal I )laning-angle with speed is y f 3o 4o 5'0" to" Angle 3.3-

'From the foregoingY it will be observedV that'iffthe optimal*planing-angle can be attained during the second conditionwhen 1,875,135 Y A 'i f Y 4 the boat endeavors to plane entirely Von thel water surface, much greater speed and much heavier loads can be successfully carried with a much smaller horse pow-er than would otherwise be necessary.

j Referring to the accompanying drawings,

A indicates the hullof a speed boat/which in-L cludes the usual bow 5, stern 6, and bottom 7. `r,The sternis provided with a cock-pit g8 4and. theboat isv provided with. an' operators seat 9. Infront of the'seatis an instrument board 10 as shown in Figure 5, andabove this board isfthe Windshield 11 as shown in Figurelp The bottom of the stern is formed with a reces`s`12 in which .is located arnormally hori-j zontally disposed fan-tailshapedhydroplane or sternplane 13, and the bottom 7 at the stern is formed withV an opening 14 which com-` 'i municatesv with-said recess. -Rigidly secured `upper end of the cylinder is :closed'by a head `18 andthe upper end ofthe post 15 is provided with a piston 19 which has sliding Contact withthe-w'all of thecylinder. A plug 2O closes Athe lower' endof the cylinderand the lower end of the post 15 extendstherev through and has sliding Contact therewith.; 1

The opening 14 is sealedbya gasketf21. `A coil spring 22 is disposed around the post 15 betweenthe lclosure plug 20 ofthe cylinder a'nd *the piston 19 andv functions to yieldably retain the sternplane 13 withintheY recess 12. i A roller 23 is journaled to rotate about a fixedV axis mountedin theb'ottom of the stern, the roller projectingr into the recess 12 andcooperating withv an arcuate track 24` formed in n the upper ,surfacel yof thesternplane. 13.

f In order to supportthecylinder 17 so as i to swing about a'horizontal axis withinv the narrow cock-pit 8,y I have-y, provided the following construction `Mountedin the cock-pit is a pair of spaced `longitudinally extending girders 25, 25 and resting upon-the girders in rear of the cylinder17 is,` abearingshoe 26 having a longitudinally extending seat 27 formed in its upper surface for receiving a bearing rod28. 1

A bearing arm 29 extends laterally and rearwardly from the cylinder intermediate its upper and lower endsandthis bearing arm isprovid'ed with upper' and lower recesses 30 and 31 respectively, the latter being seated on the bearing rod 28. *A pressure rod 32 is seated within the recess `30 and a pressure shoe 33 is disposed 'above'the pressurerod 32 and is provided with a seat 34 in its lower face for engaging said rod. Disposed in front of the bearing assembly just described and rigidly secured to each girder 25 is a pair of upwardly extending plates 35, 35. These plates extend upwardly above the pressure shoe 33 and are connected together by a cross arm 36. A clamping bar 37 is disposed'between each of the plates 35, 35 Vand'below the cross` arm 36. The rear ends of the clamping bars 37 rest on the opposite ends of the pressure shoe 33, and the forward ends of these clamping bars 37 are connected to the girders 25 by means of bolts 38 and associated adj usting nuts 39 by means of which the clamping bars 37 may be adjusted to exert more or less pressure as desired upon the pressure shoe 33 and thereby permit the cylinder 17 to be oscillated about its horizontal axis and at the same time prevent the cylinder from becoming bodily displaced from the girders. l/Vhen the cylinder 17 is swung about the bearing rod 28, the bearing shoe 33 will have sliding contact with the rear ends of the clamping bars 37.

In order to provide means for swinging the cylinder 17 about its horizontal axis, and thereby varying the angle of inclination of the longitudinal axis of the post 15 relative to the vertical and in a plane extending longitudinally of the hull, I have provided the following mechanism Supported by the girders 25 is a plate 40 and 4mount-ed on this plate is a standard 41 to whichV a lever 42 is pivoted adjacent its rear end as at 43. A link 44 has its upper end pivotally connected as at 45 to the rear end of the lever 42 and the lower end of said link is pivotally connected as at 46 to a bolt 47 which is adjustab-ly connected to an ear iixed to the cylinder 17 at a point diametrically opposite the pivot of said cylinder. Thus by operating the lever 42 the cylinder 17 together with the post 15 and the sternplane 13 can be oscillated about the horizontal axis of said cylinder and thereby vary the angular relation of the plane relative to the planing surface of the hull. In order to actuate the lever 42, I have provided a fluid pressure circuit which includes a tank 48 or source of compressedair. A cylinder 49 is mounted in the cock-pit 8 upon a transverse beam 5() through the. medium of bolts 51 and an intermediate elastic cushion 52, the openings through which the bolt-s pass being of sufficient size toi permit the cylinder to have a slight rocking movement. Mounted within the cylinder is a piston 53 and a piston rod 54 extends upwardly and is pivotally connected as at 55 to the front end of the lever r42. The fluid Vpressure circuit includes a A,control valve 56 which includes a cylinder 57 anda longitudinally movable piston The cylinder 57 is provided with two groups of ports 59, 60 and 61, and 62, 3 and A pipe connects the compressed air tank 58 with the ports 59 and 64. A pipe 66 connects the upper end of the cylinder 49 with the port 60, and a pipe 67 connects the lower end of the cylinder with the port rEhe ports 61 and 62 are exhaust ports. piston 58 is provided with two recesses or passages 68 and 69. These passages are respectively correlated with the ports 59, 60 and 61 and with lthe ports 62, 63 and 64. rlhus in one position of the piston 58 as shown in Figure 6, the compressed air tank 48 is in open communication with the upper end of the cylinder 49, and the lower end of the cylinder is in open communication with the exhaust port Thus pressure is applied to the cylinder 49 above the piston and the forward end of the lever is moved downwardly. When the piston 58 is moved inwardly, the compressed air tanl; will be placed in open communication with the lower end of the cylinder 49 and the upper end of the cylinder will be placed in open communication with the exhaust port 61, thereby providing means for swinging the lever 42 in the opposite direction. In order to pro- The vide means for manipulating the piston 58 and for retaining the same in any position of adjustment, the piston is provided with a handpiece 68 having a plurality of teeth 69 formed therein for co-operation with a spring 70 lixed to the cylinder 57.

Under some conditions, it is desirable to apply pressure to the upper end of the cylinder 17 so as to effect a relative movement b etween the pivot rod 15 and said cylinder.

For this purpose, I have provided a fluid pressure circuit which is connected to the compressed air tank 48 and which includes a control valve 71. The control valve 71 includes a cylinder 72 having three ports 73, 74 and 75 arranged in alinement. A piston 76 is slidably mounted in t-he cylinder' and is provided with a peripheral recess 7 7 adapted in one position of the pist-on to register with the port-s 7 3 and 74, and in another position to register with the port-s 74 and 75. rihe piston 76 is provided with a handpiece 78 having a series of teeth 79 formed thereon. A spring 80 is fixed to the cylinder 72 and is in constant engagement with certain of the teeth 79 so as to retain the piston 76 in any position of adjustment. A pipe 8l connnunicates with the compressed air tank 48 and with the port 73, and a pipe 82 communi-- cates with the port 74 and with the upper end of the cylinder 17 above the piston 19. The port is an exhaust port. rlhus when the piston 76 is in the position shown in Figure 7 the compressed air tank 48 is in open communication with the upper end of the cylinder 17 so as to effect a relative movement 7-5 betweentlie pist \n 19 kand they cylinder 17. *i lrWhen the piston 76 'is moved to the other po'- sition, the upperend of the cylinder 17 will trim? valve 56 is actuated so as to admit vend thereof rearwardly about the horizontal pressure to thev lower end of the cylinder 49 kand to exhaust the air from the upperend of the cylinder, to thereby swing the upper end of tie cylinder 17 forwardly and the lower pivot of the cylinder. This movement of the cylinder carries the pivot rod 15 and the plane 13' therewith, and consequently the plane is pitched downwardly and forwardly but with the track 24 in engagement with the roller 23. n This inclinationy of the plane will necessarily force the hull into acomparatively large trim angle. `As the` speed of the boat incr-eases, the trim valve 56 is actuated to slowly admit pressure to the topo-f the cylinder 49 and to exhaust air from the bottom of the cylinder, to thereby change the angle of inclination of the cylinder 49 and the pivot post 15 to a less forward inclination, which will give to the planea more upward inclination relative to the horizontal. During both adjustments of the pla-ne, the rail 24 remains in contact with the roller23`. The

Vboat is now in its planing condition and is traveling at a comparatively large inclined angle of incident. The"planing valve 71 is now actuated to slowly admit pressure to the top of the cylinder 17 which results in moving the cylinder together with the stern ofthe boat upwardly relative to the sternplane 13l which is planing on the surface of the water. This lifting movement of the stern not only compresses the spring 22, `but also effects separation between the rail 24 and the roller 23. Thus, the boat is being flattened out toward the optimal planing-angle. When the optimal planing-angle is ap'- proached the acceleration of the boat is in- -creased suddenly and the planing valve 71is closed which leaves the boat planing inthe right angle for the amount ofpowerV used.

Before the boat stops and the motor is entirely throttled down, both the trim valve and the planing valve should be pushed all the way in. The sternplane 13, by reason of the pivot post 15 being mounted for freer oscillationsn the cylinder 17 is capable of oscillating or fluttering laterally during forward travel and turning of the boat, to thereby prevent the boat from turningy over which would otherwise occur. When it is desired to reverse the direction ofthe boat, the springv 22 will press .plane llocated at and` below the sternof the the pla-ne upwardlyagainst ythe, roller 23" and therefore ther plan-e will be held against latf hull, of a plane .pivoted to thestern ofthe hull-.to swing about an axis disposed at aan angle tothe horizontal planeof the hull and means for varying the angle of inclinationr of the axis ofthe planerelative'to the vertical Y I i' 'and foradjusting the 4positionfof 'the plane vertically. f 2 I Y l -v 2. In a'speed boat, the ycombination with'la hull, of 'a plane pivoted to theistern ofthe means for varying the angle Vof inclination of eral swinging movements owing. to the inclig-` hull to swing about an' axis disposed at ank angle tofthe horizontal plane ofthe hull,

the axis of the plane relative to the vertical and for adjusting the position of the plane vertically, Aand means for retaining said axis in its adjusted position. f -V f l3. In a speed boat, the combination with a hull, of a planeipivoted to the stern of the hull to swing about an'axis disposed atan angle to the horizontal plan-e of thehull, power'operated means for varying the'angle of inclination ofthe axis'of the planerelai l n I tive to the vertical andfor adjusting the position of the Aplane lvertically,'and meansv for controlling said power operated means.

4. In a speed boat, thecombination with a i hull, of ka substantially horizontally disposed hull and having aforwardly and `upwardly inclined pivot post rigidly secured rto the forward end thereof, and means carried by the hull for freely supporting said post for oscillations about its longitudinal axis and for supporting said post for oscillations about a horizontal axis. Y j f 5. In a speed boat, the combination with a hull, of a substantially'horizontally disposed plane locatedat and below the stein of the hull and having a forwardly and upwardly inclinedpivot post rigidly secured to the forward end thereof, means carried by the hull for freely supporting said postfor oscillations about its longitudinal axis and for'supportl ing said post for oscillations about a horizon- ,tal axis'pand'means `for"'eifectinga relative for freely supporting saidfppstfor ,oscilla- .tions vabout its longitudinal axisandfor supporting saidpostfor oscillations about a horizontal axis, and means to swing the post about its horizontal axis to vary the angle of inclination of the post relative to the ver tical and in a vertical plane extending longitudinally of the hull.

7. In a speed boat, the combination with a hull, of a substantially horizontally disposed plane located at and below the stern of the hull and having a forwardly and upwardly inclined pivot post rigidly secured to the forward end thereof, means carried by the hull for freely supporting said post for oscillations about its longitudinal axis and for supporting said post for oscillations about a horizontal axis, means to swing the post about its horizontal 'axis to vary the angle of inclination of the post relative to the vertical plane extending longitudinally of the hull, and means for effecting a relative raising and lowering movement between the hull and the plane without disturbing the supporting means of the plane.

8. In a speed boat, the combination with a hull, of a substantially horizontally disposed plane located at and below the stern of the hull and having a forwardy and upwardy inclined pivot post rigidly secured to the forward end thereof, meanscarried by the hull for freely supporting said post for oscillations about its longitudinal axis and for supporting said post for oscillations about a horizontal axis, power operated means to swing the post about its horizontal axis to vary the angle of inclination of the post relative to the vertical and in a vertical plane extending longitudinally of the hull, and means for controlling said power operated means.

9. In a speed boat, the combination with a hull, of a substantially horizontally disposed plane located at and below the stern of the hull and having a forwardy and upwardy inclined pivot post rigidly secured to the forward end thereof, an arcuate track secured to the upper face of the plane, and a roller journaled on the hull for engagement with the track.

l0. In a speed boat, the combination with a y hull, of a substantially horizontally disposed plane located at and below the stern of the hull and having a forwardly and upwardly inclined pivot post rigidly secured to the forward end thereof, an arcuate track secured to the upper face of the plane, a roller journaled on the hull for engagement with the track, and a spring mounted on the hull f around the post and cooperating with the latter to yieldably maintain the track and roller in engagement.

ll. In a speed boat, the combination with a hull, of a subtsantially horizontally disposed plane located at and below the stern of the hull and having a forwardly and upwardly inclined pivot post rigidly secured to the forward end thereof, means carried by the hull for freely supporting said post for oscilhorizontal axis, an arcuate track secured to the upper face of the plane, and a roller journaled on the hull for engagement with the track.

12. In a speed boat, the combination with a hull, of a substantially horizontally dis- -posed plane located at and below the stern of the hull and having a forwardlyy and upwardly inclined pivot post rigidly secured to' the forward end thereof, means carried by the hull for freely supporting said post for oscil` -lations about its longitudinal axis and for -supporting said post for oscillations about a horizontal axis,an arcuate track secured to the upper face of the plane, a roller journaled on the hull for engagement with the track, and a spring mounted on the hull around the post and cooperating with the latter to yieldably maintain the track and roller in engagement. 13. In a speed boat, the combination with a hull having an opening in the bottom of the stern, of a'cylinder located in the hull with one end in register with said opening, means carried by the hull for supporting the cyl inder to'swing about a horizontal axis, a sub; stantially horizontally disposed plane located at and below the stern of the hull and having a forwardly and upwardly inclined pivot post rigidly secured to the forward end thereof and extending through the opening of the hullinto the cylinder for free rotation there in, `means for sealing the opening, and means to swing lthe cylinder together with the post and plane about the horizontal axis vof the cylinder. v `V14. In a speed boat, the combination with a vhull havingan 'opening in the bottom of the' stern, of a'fcylin'der located in the hull with one end in register with said opening, means carried by the hull for supporting the cylinder to swing about a horizontalaxis, a substantially horizontally disposed plane located at andy below the stern of the hull and having a forwardly and upwardly inclined pivot post rigidly secured to the forward end thereofl and extending through the open'- ing of the hul-l into the cylinder for free rotation therein, an arcuate track secured to the upper face of the plane, a roller iournaled on the hull for engagement, with the track, aspring mounted on the hull around the post and cooperating with the latter to yieldably maintain the track and roller in engagement, and means to swing the cylinder together withl the post and plane about the horizontal axis of thecylinder.

` y15.In a speed boat, the combination with a hull'having an opening inthe bottom of the stern,of a Vcylinder located in the hull' with one'end in register with said opening, means carried by the hull for supporting the cylinder to swing about a horizontal axis, a substantially horizontally disposed plane located l6, A s 11,875,135"

' -arand'beiawthetemorthe-hanandhavinga y y 5 4 into the cylinder for free rotation therein,

@forwardly and upwardly inclined pivotypost z Y `rigidly secured to theforward endthereof and Aextendingthrough theopening of thehull J means for sealing the opening, a piston-fixed l tothe upper end of thepost, a eoil` spring Vlocated within the cylinderV between the lower yjend thereof and saidpiston for normallyurg- V10 ing the yplane upwardly towards the hull, fluid i gether with the post and plane about the 'horizontal'axisof thereylinder.

16,v Ina speed boatq the eombinationvwith Ya hullhaving anopeningin the bottom of the stern, of a eylinderloeated in thehull lwith i 20 one pend ingregister with said opening, means carried by the hulll for supporting the eylinderto swing abouta horizontal axis, a substantiallyhorizontally disposed'plane located g atand below thestern of the hull and `havingla forwardly and upwardlyinclined pivot J'Xed to the upper end of the post, a eoilspring l l f located within-the eylinderbetween the lower Y j post rigidlysecured to the forward end thereof andv extending through the opening ofthe hull into the cylinder for free rotation therein,' means for sealing thel opening, a piston 1 end fther'eof and said piston VCfor lnormally y -v urging the plane upwardlytowards the'lhull, i luidpressure means cooperating with'the cyl-Y inderA above the piston lto liftthe boat stern i relativetothe plane andiagainst the tension .i Y

Y `of the spring, meansto swing the cylinder togethen Lwith the postand plane about .the horizontal "axis of `the cylinder, saidswinging means including a lever having connection with the cylinder at a point vdiametrieally-op- Y, positethehorizontal-pivot thereof, and 2a u i uidpressure Vcircuit includinga cylinder and v f Vpiston having. operativev VConnection with the lever'.A f Y 1 yi Q .y

' lfLIn agspeedboat, theeombinationiwith a hull,'of a ysubstantiallyr horizontally; dis-v v Y lposed planeloeated'at and belowuthe stern v Y I l' 0f the hull andhaving a forwardly'and up-V wardly inclined pivot post rigidlyisecrured to -V the forwardend thereof, means Carried by the'- -v hull Y forf'freely supporting said post for'os-k Cillations' about its longitudinallaxs and yforv supporting said post for loscillations about ai' A hor1zontalaXis,meansto swing thepostabout itsfhorizontalaxis to vary the angle of inv Y elination of thep'ost. relative to the vertical f and inv aV vertical plane kextending longitudinally of the hull, and'meansQfor retaining said v. post in an adjusted position of inclination; i t

' 1615 if', f 'A y Inr rtestimony-whereof 'Iaflix my signature;A

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